Monday, June 5, 2023

1995 Pont de Normandie over Seine River at La Havre, France


Street View, Jul 2021

Highway Engineering Discoveries posted
The Pont de Normandie (English: Normandy Bridge) is a cable-stayed road bridge that spans the river Seine linking Le Havre to Honfleur in Normandy, northern France. Its total length is 2,143.21 metres (7,032 ft) – 856 metres (2,808 ft) between the two piers. It is also the last bridge to cross the Seine before it empties into the ocean. Despite being a motorway toll bridge, there is a footpath as well as a narrow cycle lane in each direction allowing pedestrians and cyclists to cross the bridge free of charge.  
[The grade is 6%. I have not been able to find the clearance.]

Why are there piers under the backstayed spans? Normally the cables hold the dock over the back spans as well as the main span.
bouyges-tp, cropped
"When it was inaugurated in 1995, the Normandy Bridge was the largest cable-stayed bridge in the world. Crossing the Seine estuary in one go over a distance of 2.14 kilometres [1.3 miles], this French structure links the industrial centre of Le Havre to the tourist bank of Honfleur....To cross a 6% slope, the concrete decks of the north access viaduct had to be installed using a new technique patented by Bouygues at the time: the so-called lift-launch method."

"With the main span width of 856m, pylon height of 203m (666'), and the total length of 2,141m, the bridge is one of the longest cable-stayed bridges in the world."

3D Satellite

By © CitronCC BY-SA 3.0Link

"It was constructed between 1988 and 1995 and when it was built it was the longest bridge in the world. It also held the record for the longest distance between piers for any cable-stayed bridge at the time. The records for the longest distance between piers and overall length were lost, respectively, to the Tatara Bridge in Japan and the Rio-Antirrio bridge, which spans the Gulf of Corinth....The bridge cost $465 million to build. The main reason for building a cable-stay bridge instead of a suspension bridge was for its improved stability in high wind at a competitive cost. The Normandy Bridge has 184 cable stays to support the weight of the deck, which is 23.6 m wide in total and allows for four lanes of traffic and two pedestrian walkways. The two pylons holding the cables are 214 m [700'] in height and weigh 20,000 t....The stretch between the piers is 856 m (2,808 ft)....On completion, the bridge was tested with a weight of Lorries equal to 16,000 t to assess its load limit and strength.....The earth's curvature and the immense length of the bridge required that the distance between the pylons had to be 2 cm greater at the top than at the base." [azobuild, this reference has some construction details.]

normandie-tourisme, this webpage has more photos of the bridge
It cose 419m euros.
"It has been resist winds of over 300 km/h (that’s 186 mph)!...Each cable can be removed individually for maintenance."

Highway Engineering Discoveries posted
Normandy Bridge, France

"Before the opening of this bridge in 1995, traffic had to go another 40 kilometers or more to get from the Le Havre side of the Seine to the Honfleur side. As a main route for traffic coming from the Channel Tunnel (or Chunnel) and going south in France, the opening of this new bridge was hailed as a great advance."
"Model of the support pier from the Normandy Bridge museum - original"
The deck is a box girder, but the girder is made with steel in the main span and with prestressed concrete for the other spans. 
Street View, Sep 2023
The cables between the cables are for vibration control. tourdefrance-bridges calls them "needles."

2 of 5 photos on bouygues-construction:


1 comment:

  1. Interesting. I've watched the new Gordie Howe International Bridge between Detroit and Windsor go up. The towers are 220 meters tall (722 feet), and the full length is 2.5 km with a main span of 853 meters, so very comparable.